title: Rapid diagnosis of bacterial meningitis by the detection of a fatty acid marker in CSF with gas chromatography-mass spectrometry and selected ion monitoring.
abstract: A chemical marker of bacterial meningitis was sought by comparing derivatives of sterile cerebrospinal fluid (CSF) with cultures of organisms in spinal fluid and artificial media. The technique of gas chromatography-mass spectrometry with selected ion monitoring (GC-MS-SIM) was used, optimised for the analysis of fatty acids. Twenty candidate ions were screened, and an ion of mass: charge ratio (m/e) 268 was chosen for detection in clinical specimens. The origin of this marker is unknown, but it is probably the molecular ion of a C16:1 fatty acid. In 135 clinical specimens of CSF examined, the m/e 268 ion was found to be a useful marker for the common organisms that cause bacterial meningitis, giving a sensitivity of 88% and a specificity of 98%. The method was more rapid and more sensitive than conventional microscopy and culture, but CSF containing coagulase-negative staphylococci, Mycobacterium tuberculosis, Cryptococcus neoformans and some other uncommon pathogens gave inconsistent results. Many organisms produced characteristic ion profiles with multiple-ion monitoring, and this method of chemical analysis holds promise for the rapid diagnosis of bacterial infections to genus or species level.
authors.affiliation: Department of Microbiology, Chinese University of Hong Kong, Shatin.
authors.forename: G L
authors.initials: GL
authors.lastname: French
authors.forename: C Y
authors.initials: CY
authors.lastname: Chan
authors.forename: D
authors.initials: D
authors.lastname: Poon
authors.forename: S W
authors.initials: SW
authors.lastname: Cheung
authors.forename: A F
authors.initials: AF
authors.lastname: Cheng
mesh_terms: D015415:Biomarkers / Q000134:cerebrospinal fluid; D003453:Cryptococcosis / Q000134:cerebrospinal fluid / Q000175:diagnosis; D005227:Fatty Acids / Q000134:cerebrospinal fluid*; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000032:analysis; D006094:Gram-Positive Bacteria / Q000032:analysis; D006801:Humans; D008581:Meningitis / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D009164:Mycobacterium Infections / Q000134:cerebrospinal fluid / Q000175:diagnosis; D013203:Staphylococcal Infections / Q000134:cerebrospinal fluid / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D005227:Fatty Acids